Improvement in hoisting-tackle



2 Sheets-Sheet 1. T. A. WESTON. HOISTI-NG-TACKLE.

No. 1947019. Patented Aug. 7,1877.

UNITED STATEs PATENT OFFICED THOMAs A. WESTON, OF sTAMFonD, CONNECTICUT, AssIeNOE To THE YALE LOOK MANUFACTURING COMPANY, OF sAME PLACE.

` IMPROVEMENT IN Hois'rlNG-TACKLE.

Specilieation forming part of Letters Patent No. 194,019, `dated August 7, 1877; application Iiled April 18, 1877. I

To all whom 'it may concern Be it known that I, THOMAS A. WESTON, of Stamford, Connecticut, have invented a new and useful Improvement in Hoisting- Tackle, of which the following is a specification:

The object of my invention is to combine pulley-blocks with simple gearing, through the medium of which the capacity of said blocks for raising heavy weights shall be increased without materially increasing the weight or bulk of the blocks.

In the accompanying drawings, Figure l is a side view, and Fig. 2 an edge view, illus trating the application of my invention to the differential. pulley-blocks for which Letters Patent were granted to me on the 6th day of August, 1867 5 reissued July 9, 1872 Fig. 3, a sectional plan on the line 1 2, Fig. 2; Figs. 4 and 5,A a side view and section of the differential block, drawn to an enlarged scale, and illustrating my invention; and Figs. 6 and 7, a side view and section with modified attachments for the gearing.

It should be understood in the outset that,l

although I have illustrated and am about to describe my invention as applied to my patented pulley-blocks, to which it is especially well adapted, the system of gearing can be usedin connection with ordinary blocks and hoisting-tackle.

In Figs. 1,2, and 3, A and A' represent the differential pulleys, carried by a frame consisting of the pendent arms a. a, a cross-bar, b, to which thehook d is swiveled, horizontal arms e e, forming part of the pendent arms, and guards ff, secured to the said horizontal arms.

The lower pulley-block B is of the usual construction, and the hoisting-chain, the course of which is shown by dotted lines, is arranged in a manner precisely similar to that described4 in my aforesaid patent, in which the said hoisting-chain was manipulated in raising and lowering weights.

In my present improvement I use an' additional endless chain, D, to be manipulated by the operator, this chain being adapted to a pulley, E, on a shaft, F,`which has its bearings in the frame H, passes through and turns independently of the differential pulleys, and v is provided at-the end oppositeto that which carries the drivin g-pulley E with a pinion, G, the teeth of which gear into those of a wheel,

` l, on a short counter-shaft, M, which has its of the two differential pulleys A A'.

It will be evident that, in operating the differential pulleys by the endless chain D and chain-wheel E through the medium of the gearing described, such an increased leverage is obtained that the capacity of the blocks for raising heavy weights at a comparatively tritlin g exercise of power is increased, `and this without much additional expense, and without rendering the blocks as cumbrous as they become when the other systems of gearing which have been heretofore invented are made use of.

While the shaft may pass directly through the eyes of the differential pulleys, and turn in contact therewith, it is 'preferable in all cases to have an intervening sleeve, m.

As regards the detailed construction of the block, it may be varied without departing from the main feature of the invention.

In Figs. 4 and 5, Sheet 2, one of the pendent arms consists of a plate, c, and link al, and the other of the plate a2 and link a3; and the sleeve m, on which the differential pulleys revolve, is secured at one end to the plate a and link al, and at the other end to the link a3, the plate a2, adjacent to this link, being bent to the form of a yoke toaccommodate the gearing, and the lower end of this plate being secured to a continuation of the link a3, and also to a plate, P, which is fitted to the sleeve, and to the upper end of which is secured the counter-shaft M, the latter being stationary in this `modification of my invention, and its outer end being supported by the plate c2.'

rEhe wheel I, which is drivenV by the pinion G on the driving-shaft F, and the pinion J, which gears into the internal wheel of the differential pulley, are made inrv one piece, and revolve together on the. stationary countershaft.

In the modification shown in Figs. 6 and 7 there-is, in addition' to the link a3 and the yoke-plate c2, an intermediate plate, a4, which forms one of the bearings for the counter-shaft M, which, i-n the present instance, is arranged to revolve, and the outer bearing ot' which is in the yoke-plate az.

There is one feature common to all modifications of my invention, and that is the continuation w of the guards for the chain of the differential pulleys, so as to form a guard for the endless driving-chain. This guard for the driving-pulley may, however, be attached to l any part of the frame H of the pulley-block.

y It will be readily seen Without description that an independent endless driving chain and pulley, with the system of gearing whichl have-described, may be combined with an orY dinary pulley-block. I

I claim as my inventionv l. The combination, in a pulley-block, of a hoisting pulley orpulleys, a driving-shaft passing through the hoisting pulley or pulleys, a driving-pulley secured to the said shaft, and the system of cog-wheels having xed central axes, substantially as described, whereby the said driving-shaft is geared to the said hoist ving pulley or pulleys, as herein set forth.

2. The combination, in a differential pulleyblock, of the differential pulleys, of different diameters, and rigidly secured to each other,

a driving-shaft passing through the same, a driving-pulley secured to said shaft, and a system of gearing, substantially as described, whereby the said driving-shaft is geared to the said differential pulleys.

3. An improved pulley-block containing the following elements, viz: a hoisting pulley or pulleys, a driving pulley and shaft, and a System of cog-wheels for communicating motion from. the driving-pulley to the hoisting-pulley, all the said cog-Wheels having Xed central .axes radially within thecircumference of the hoisting-pulley, substantially as described.

v4. In a lpulley-block, the combinatlon of a hoisting pulley or pulleys, provided with toothed gearing, with the driving-pinion G and pinions 1 J, radially within the circumference of the said pulley, as set forth.

5. The combination, in a pulley-block, ofthe hoisting pulley or pulleys,'the driving-shaft F, and the intermediate sleeve m, on which the said pulley or pulleys turn, as described.

6. The plate P, fitted to and combinedwitli the sleeve m, and secured to the block-frame, and forming a support for one'end of the fixed counter-shaft M.

In testimony whereof'l have signed my nam to this specification in the presence of two subscribing Witnesses'. Y

THOMAS A. WESTON. 

